In order to produce silicon wafers, processes including slicing a silicon ingot and polishing the silicon wafers are performed. For instance, a silicon ingot is sliced while supplying processing fluid to a wire. A silicon ingot is sliced according to either a loose abrasive method in which the silicon ingot is sliced while dispersing abrasive grains in the processing fluid or a fixed grain method in which the silicon ingot is sliced with the abrasive grains being rigidly attached on a surface of a wire.
The processing fluid used for the loose abrasive method includes an aqueous processing fluid containing, for instance, a friction coefficient reducer, an auxiliary corrosion-resistance agent and the like. The friction-coefficient reducer contained in the processing fluid is an unsaturated fatty acid. The auxiliary corrosion-resistance agent is benzotriazole (see Patent Literature 1).
The processing fluid used for the fixed grain method includes an aqueous processing fluid containing, for instance, glycols, carboxylic acids, alcanolamines and the like (see Patent Literature 2).